JP2001335768A - Pressure-sensitive adhesive composition and sheet for carrying information obtained by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a pressure-sensitive adhesive composition exhibiting strong fixation to paper, giving an adhesive film having strong cohesive force and not suffering from abrasion or dropout of an adhesive when running through a printing machine or a printer, and to prepare a sheet for carrying information obtained by using the pressure-sensitive adhesive composition. SOLUTION: The pressure-sensitive adhesive composition comprises 100 pts. mass of an adhesive base comprising 100 pts.mass of the solids content of a natural rubber-based latex having methyl methacrylate graft-copolymerized therewith and incorporated therewith a styrene-rich SBR latex having a styrene content of 70-95% in an amount such that the solids content thereof is 5-50 pts.mass and 30-100 pts.mass of a particulate filler having non-affinity to the adhesive base.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive composition and an information-bearing sheet using the same, and more particularly, to a folded sheet having an information-bearing surface formed by folding or cutting. , An information transmission sheet having a confidentiality such as a superimposed sheet, an information transmission sheet such as an office sheet such as a scalable sheet and copy paper, and a pressure-sensitive adhesive composition used for the same Things.

[0002]

2. Description of the Related Art Conventionally, in an information carrying sheet that carries information on a superimposed surface, the entire surface of the superimposed surface is usually arranged so that the superimposed surfaces are adhered to each other so as to be in contact with each other when they are superimposed. An adhesive layer of a pressure-sensitive adhesive is provided in a specific portion or linearly. This pressure-sensitive adhesive is also referred to as a self-adhesive pressure-sensitive adhesive, and is a type in which polymers are adhered to each other by self-diffusion by applying a high pressure while the adhesive layers are in contact with each other. Depending on the type of object and the degree of pressure, permanent adhesiveness and removable adhesiveness are realized.

Conventionally, the main component of the pressure-sensitive adhesive used in this type of information-carrying sheet is generally a natural rubber-based latex of a methyl methacrylate graft copolymerized natural rubber or a natural rubber-based latex of a methyl methacrylate / styrene graft copolymerized. It is included as a component. However, pressure-sensitive adhesives containing a natural rubber-based latex based on methyl methacrylate graft copolymer have low adhesiveness to paper and a low cohesive force of the adhesive film. However, there is a problem that the steel is worn and falls off.

[0004]

SUMMARY OF THE INVENTION A first object of the present invention is to provide a pressure-sensitive adhesive composition containing a methyl methacrylate graft copolymerized natural rubber-based latex as a main component, which solves the conventional problems. The purpose of the present invention is to provide a pressure-sensitive adhesive composition in which the adhesive property and the cohesive force of the adhesive film are both strong, and the adhesive does not wear out or fall off while running on a printing machine or a printer. A second object of the present invention is to provide an information carrying sheet using such a pressure-sensitive adhesive composition.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventor has found that a specific amount of a specific styrene-rich SBR latex is blended with a specific styrene-rich SBR latex in a methyl methacrylate graft copolymerized natural rubber-based latex. The present inventors have found that the problem can be solved by using a pressure-sensitive adhesive composition containing a specific amount of a fine-grained filler exhibiting incompatibility with an adhesive base, and have completed the present invention.

That is, the pressure-sensitive adhesive composition according to the first aspect of the present invention is applied to a superposed surface of a sheet, and forms an adhesive layer which does not adhere in a normal state by a drying treatment. A pressure-sensitive adhesive that is brought into contact with and applied with a predetermined pressure so that the superposed surfaces can be peelably adhered to each other. The styrene-containing methyl methacrylate graft copolymerized natural rubber-based latex has a solid content of 100 parts by mass. The styrene-rich SBR latex having an amount of 70 to 95% is blended so that the solid content thereof is 5 to 50 parts by mass. From 30 to 100
It is characterized by being blended by mass.

According to the pressure-sensitive adhesive composition according to the first aspect of the present invention, a specific amount of a styrene-rich SBR latex having a specific styrene content is blended with a methyl methacrylate graft copolymerized natural rubber-based latex. Since a pressure-sensitive adhesive composition in which a specific amount of a fine-grained filler exhibiting incompatibility with the base material is used, the adhesive layer is applied to the overlapping surfaces of the sheets and does not adhere in a normal state by a drying process. Is formed, and after the superposed surfaces are brought into close contact with each other by applying a strong pressure to adhere them to each other, they can be easily peeled off when necessary. The pressure-sensitive adhesive composition according to claim 1 of the present invention has both strong fixability to paper and a strong cohesive force of an adhesive film, and the adhesive is worn while running on a printing machine or a printer. Never fall off.

According to a second aspect of the present invention, there is provided an information carrying sheet comprising an adhesive layer comprising a large number of fine convex patterns of the pressure-sensitive adhesive composition according to the first aspect on a predetermined portion of a superposed surface of a base sheet. It is characterized by having.

In the information carrying sheet according to the second aspect, the pressure-sensitive adhesive composition according to the first aspect is applied to a predetermined portion of the superposed surface of the base sheet using, for example, a gravure coater.
By forming an adhesive layer consisting of a large number of fine convex patterns that do not adhere in the normal state by the drying process, and applying high pressure while keeping the superposed surfaces in contact with each other, it is possible to obtain sufficient adhesive force by bonding. It can be easily peeled off when necessary. The adhesive layer has a suitably strong fixing property to paper and a cohesive force of the adhesive film, and does not wear out or fall off while running a printing machine or a printer.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The pressure-sensitive adhesive composition of the present invention forms an adhesive layer which does not adhere in a normal state, adheres under pressure, and can be peeled off when necessary, that is, forms a so-called adhesive layer, and comprises an adhesive base. A mixture prepared by mixing a styrene-rich SBR latex having a styrene content of 70 to 95% with respect to a solid content of 100 parts by mass of a methyl methacrylate graft copolymerized natural rubber latex so that the solid content is 5 to 50 parts by mass. The adhesive base is mixed with 30 to 100 parts by mass of a fine particulate filler having incompatibility with 100 parts by mass of the adhesive base.

The methyl methacrylate graft copolymerized natural rubber latex used in the pressure-sensitive adhesive composition of the present invention is a natural rubber latex graft-copolymerized with methyl methacrylate. Natural rubber latex commonly used as an agent can be used.

The styrene-rich SBR latex used in the pressure-sensitive adhesive composition of the present invention is a synthetic rubber latex generally used as a component of an adhesive, and is an emulsion in which styrene-rich SBR is dispersed in an aqueous solvent. It is. At this time, an emulsifier is required to stabilize the dispersion of the latex particles. As the emulsifier, an anionic surfactant such as rosin soap, naphthalene sulfonate, fatty acid soap, or alkylbenzene sulfonate is generally used. Can be The styrene content is 70-95%, preferably 80-95%. 7
If it is less than 0% or more than 95%, the fixability to paper and the cohesive strength of the adhesive film may not be improved.

Specific examples of commercially available styrene-rich SBR latex used in the pressure-sensitive adhesive composition of the present invention include, for example, Nipol 2507H (Zeon Corporation), Asahi Kasei Latex L-1638 (Asahi Kasei Corporation), JSR synthetic rubber latex 0602 (JSR
Co., Ltd.).

The mixing ratio of the styrene-rich SBR latex is based on 100 parts by mass of the solid content of the styrene-rich SBR with respect to the solid content of the methyl methacrylate graft copolymerized natural rubber latex.
The BR latex is blended so that the solid content is 5 to 50 parts by mass, preferably 10 to 30 parts by mass.

In the present invention, it is preferable to blend the styrene-rich SBR latex such that the total amount of methyl methacrylate graft-copolymerized with natural rubber and the styrene-rich SBR latex is in the range of 20 to 60 parts by mass.

The mixing ratio of the methyl methacrylate graft copolymer natural rubber-based latex and the styrene-rich SBR latex depends on the adhesive strength of the adhesive layer, the fixability to a base sheet made of a material such as paper and synthetic paper, and the adhesive layer coating. It needs to be adjusted appropriately since it affects the balance with the cohesive force of the rubber.
When the solid content of the styrene-rich SBR latex is less than 5 parts by mass and the amount of the methyl methacrylate graft copolymerized natural rubber-based latex is excessive, the fixability of the adhesive layer to the base sheet surface decreases, and conversely, the styrene-rich SBR latex When the solid content exceeds 50 parts by mass, the adhesive force between the adhesive layers on the superposed surface is reduced, and an appropriate peeling performance cannot be obtained. Therefore, the blending ratio of the methyl methacrylate graft copolymer natural rubber-based latex and the styrene-rich SBR latex needs to be in the above range.

The thus obtained adhesive base comprising a mixture of a methyl methacrylate graft copolymerized natural rubber-based latex and a styrene-rich SBR latex may, if desired, contain additives commonly used in pressure-sensitive adhesives. For example, a tackifier, a viscosity modifier, an antioxidant, a stabilizer, a colorant, and the like can be added.

In the pressure-sensitive adhesive composition of the present invention, a fine particle filler having incompatibility with the adhesive base is blended. As the fine particle filler, one having a small affinity for the adhesive base and having a regular particle shape is preferably used. Such materials include, for example, various types of starch, synthetic zeolite, fine spherical acrylic resin, fine spherical methacrylic resin, fine spherical polyethylene, spherical alumina, glass powder, shirasu balloon, activated clay, and the like. These fine particle fillers may be used alone or in combination of two or more.

Further, in the pressure-sensitive adhesive composition of the present invention, 30 to 100 parts by mass of a fine particle filler having an incompatibility with the adhesive base is added to 100 parts by mass of the adhesive base. Preferably from 40 to 100 parts by mass, more preferably 5
It is blended in the range of 0 to 100 parts by mass. If the compounding amount of the fine particle filler is too small at less than 30 parts by mass, the blocking resistance may be reduced, or the adhesive force may be too strong to be peeled off. Power is too low.

The pressure-sensitive adhesive composition of the present invention is applied to the base sheet surface by an application means such as a gravure coater, flexo, air knife coater, bar coater, etc. It can be suitably used for postcards, spreadsheets, notices, various cards, etc., which have a double-sided surface that is temporarily adhered in various forms such as superposition, but can be easily peeled off as needed.

Next, as the substrate sheet to which the pressure-sensitive adhesive composition of the present invention is applied, in addition to ordinary paper, synthetic paper or a synthetic film of polyethylene, polyethylene terephthalate, polypropylene, vinyl chloride or the like is used. You can also. When using these synthetic films, the surface of the base sheet is preferably subjected to a surface treatment such as a mat treatment or a corona treatment. The amount of the pressure-sensitive adhesive composition applied to the surface of the base sheet is from 1 to 30 g / m ² , preferably from 3 to ²⁰ g, due to the adhesiveness and peelability of the adhesive layer.
/ M ² , more preferably 5 to 15 g / m ² .

The information carrier sheet of the present invention may be provided with an adhesive layer comprising a large number of fine convex patterns made of the pressure-sensitive adhesive composition of the present invention on at least a part of the surface of the base sheet. It is important. The method of providing an adhesive layer comprising a large number of fine convex patterns of the pressure-sensitive adhesive composition of the present invention on the surface of the base sheet is not particularly limited,
Even if the coating method using a gravure coater is economical, it has information on characteristics such as the adhesive property of the adhesive film and the cohesive strength of the adhesive film are both strong, and the adhesive does not wear or fall off while running on a printing machine or printer. This is the most preferable method because it can be easily applied to the carrier sheet. When coated with an air knife coater, the surface of the adhesive layer becomes uniform, so that it is necessary to mix more than 100 parts by mass of a fine particulate filler with respect to 100 parts by mass of the adhesive base. According to the application method according to the above, the fine particulate filler is 30
To 100 parts by mass.

This is because, when coated with an air knife coater, the fine particulate filler is applied evenly and uniformly on the substrate sheet surface, but the gravure coater is applied on the substrate sheet surface in a concave pattern of the mesh of the engraving roll. Thus, an adhesive layer comprising a large number of fine convex patterns of the pressure-sensitive adhesive composition of the present invention can be provided by one application. As shown in Table 1, the concave pattern of the mesh of the engraving roll has a pyramid shape having different peak widths (a), peak-to-peak widths (b), valley widths (c), and peak heights (d). There are lattice type and the like, and the pressure-sensitive adhesive composition is held in these concave portions. Usually, a gravure offset method is used in which the pressure-sensitive adhesive composition is once transferred from an engraving roll to a transfer roll (print roll) and then applied to a base sheet. The size and shape of the concave pattern of the mesh differ in the size and shape of the fine convex pattern of the adhesive layer of the pressure-sensitive adhesive composition of the present invention provided on the surface of the base sheet. Since the pressure-sensitive adhesive composition of the present invention spreads at the time of coating with a gravure coater, it goes without saying that a fine convex pattern having the same size and shape of the concave pattern of the mesh is not formed.

[0024]

[Table 1]

At the time of coating with a gravure coater, the adhesive base spreads more rapidly than the finely divided filler silica gel or wheat starch, so that the central part of the convex pattern of the applied pressure-sensitive adhesive composition of the present invention is applied. The composition is such that silica gel and wheat starch as fine fillers are more than the composition of the original adhesive. Therefore, adhesion to the base sheet surface is
It is believed that this is done by the adhesive base in the convex pattern and the spread adhesive base.

The blocking resistance of the information carrier sheet of the present invention is improved by silica gel or wheat starch as a fine filler, but the adhesive layer of the pressure-sensitive adhesive composition of the present invention has a large number of fine convexes. Because it is formed from a pattern,
The blocking resistance of the information carrier sheet is more improved than when it is uniformly applied. In addition, the fine filler in the convex pattern is fixed with an adhesive base, and the convex pattern is adhered to the base sheet surface with the spread adhesive base. Thus, the adhesive layer of the pressure-sensitive adhesive composition of the present invention is more firmly fixed to the base sheet surface than when the pressure-sensitive adhesive composition of the present invention is uniformly present on the base sheet surface. In addition to the fact that the amount of the fine particulate filler is small, the fine particulate filler does not fall off, and it is possible to obtain an information carrier sheet with greatly improved printability, printer suitability, sealer suitability, etc. it is conceivable that. The reason why the information carrier sheet of the present invention having the above excellent characteristics can be obtained is not limited to this concept. Furthermore, by pressing the formed peelable adhesive layer with a pressure roller, the blocking resistance can be further improved.

Next, the configuration of the information carrying sheet of the present invention will be described in detail with reference to the accompanying drawings. Here, FIG.
FIG. 2 is a front view of the three-fold postcard of the present invention, FIG. 2 is a rear view of the postcard, FIG. 3 is a cross-sectional view taken along line XX of FIG.
FIG. 5 is an explanatory view of the state when the postcard of FIG. 1 is folded, FIG. 5 is a front view of the folded postcard of the present invention, FIG. 6 is a developed view of the back side of the postcard, and FIG. 8 and FIG. 8 are front development views of the partially folded postcard according to the present invention, FIG. 9 is a rear development view of the postcard, and FIG. 10 is a state explanatory view when the postcard of FIG. 8 is folded.

First, a three-fold postcard 1 shown in FIGS. 1 to 3 is composed of a base sheet 2 having a size three times the size of a standard postcard, and is divided into three regions by folding lines 3a and 3b. is there. On the front surface of the left section area A, print destination information such as a zip code, a destination name, and an address.
However, concealment information prints 5 are printed directly on the base sheet 2 on the front and back surfaces of the central partitioned area B and on the front face of the right partitioned area C. Further, the pressure-sensitive adhesive composition of the present invention is applied to the entire front surfaces of the divided regions B and C and the whole back surfaces of the divided regions A and B of the printed base sheet 2 by the adhesive layer 6 which can be peeled off. Is formed. As shown in FIG. 4, the three-fold postcard 1 configured as described above folds the overlapping surface of each section into a Z shape at folding lines 3a and 3b to bring the adhesive layers into contact with each other. By pressing with a sealer, the adhesive layer 6 is activated and adhered.

Next, a two-fold postcard 11 shown in FIGS. 5 and 6 is composed of a base sheet 2 having a size twice as large as a standard postcard size, and is divided into two regions D and E by a folding line 3 at the center. It is what is divided. A destination information print 4 such as a postal code, a destination name and an address is printed on the front surface of the left section area D, and a concealment information print 5 is printed directly on the base sheet 2 on the back sides of the section areas D and E. . further,
The pressure-sensitive adhesive composition of the present invention is applied to the entire back surface of the divided areas D and E of the printed base sheet 2 to form a peelable adhesive layer 6. As shown in FIG. 7, the two-fold postcard 11 configured as described above is folded and pressed at the fold line 3 so that the adhesive layers on the right and left rear surfaces are in contact with each other, similarly to the above-described three-fold postcard. The adhesive layer 6 is activated and adhered.

8 and 9 is composed of the base sheet 2 having a size 1.5 times the size of the standard postcard. And G. The postal code, address,
A destination information print 4 such as an address, and a concealment information print 5 is printed directly on the base sheet 2 on the back surface of the right side divided area G. Further, the pressure-sensitive adhesive composition of the present invention is applied to the entire back surface of the partitioned area G of the printed base sheet 2 and a part of the back face of the partitioned area F which is overlapped when the partitioned area G is folded along the folding line 3. Adhesive layer 6 to which object is applied and which can be peeled off
Are formed. As shown in FIG. 10, the partially folded postcard 21 configured as described above is folded and pressed at the folding line 3 so that the adhesive layers on the back surfaces of the left and right sections are in contact with each other, similarly to the above-described two-fold postcard. Thereby, the adhesive layer 6 is activated and adhered.

Further, the peelable adhesive layer formed by the pressure-sensitive adhesive composition of the present invention itself also has a receptivity for printing ink and toner. Alternatively, additional information (not shown) can be printed by a non-impact printer.

[0032]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited to these Examples. Example 1 Methyl methacrylate (MMA) graft copolymer natural rubber (NR) 1
And 100 parts by weight of MMA graft copolymerized natural rubber emulsion (solid content) obtained by mixing and mixing 100 parts by weight of MMA and 10 parts by weight of MMA.
Silica gel 25 was added to 100 parts by mass of an adhesive base containing BR latex (Nipol 2507H, Nippon Zeon Co., Ltd.) or Asahi Kasei Latex L-1638 (Asahi Kasei Corporation) so that the solid content was 10 parts by mass. The pressure-sensitive adhesive composition of the present invention was prepared by blending parts by mass and 135 parts by mass of starch. The pressure-sensitive adhesive composition of the present invention is applied to a 70 kg high-quality paper by a gravure offset method.
Coating at a rate of 0 g / m ² to form an adhesive layer,
Heating was performed at 120 ° C. for 30 seconds to perform a drying treatment. The 90 ° peeling (T-peeling) adhesive strength, blocking resistance, and abrasion resistance immediately after the production of the information carrying sheet thus produced were evaluated by the following methods. The evaluation results are shown in Table 2.

(1) Method of measuring 90 ° peeling (T-shaped peeling) adhesive force: The obtained information carrying sheet was cut into a width of 25 mm and a length of 100 mm to prepare a sample. And applied pressure of 7 MPa. Test method for peeling adhesive strength of adhesive JIS K685
Autograph AGS50 (manufactured by Shimadzu Corporation) according to 4.
Is used to measure the 90 ° peeling (T-peeling) adhesion. ◎: 100 to 150 (gf / 25 mm) ：: 150 to 200 (gf / 25 mm) or 50 to
100 (gf / 25 mm) Δ: 200 to 300 (gf / 25 mm) or 30 to
50 (gf / 25 mm) ×: 300 (gf / 25 mm) or more or 30 (gf / 25 mm)
/ 25mm) or less ◎: Excellent, ○: Good, △: Acceptable, ×: Not Acceptable

(2) Blocking resistance 500 g / c
After applying a pressure of m ² and leaving at 50 ° C. for 30 minutes, the peel strength was measured. Blocking resistance (peel strength) (g / c
m): 2 or less, ◎;
Those in the range of 5 to 10 were marked with Δ, those with 10 or more were marked with x. For the measurement of the peel strength, a tensile tester Autograph AGS50 manufactured by Shimadzu Corporation was used. ◎: Excellent, ○: Good, △: Acceptable, ×: Not Acceptable

(3) Wear Resistance Using a paperboard abrasion tester, the surface of the adhesive layer when worn 100 times was visually judged to determine the degree of wear. As a result, the ratio of the broken area of the tested area was 10% or less: 、, 30% or less: 、, 50% or less: Δ, 51% or more: ×. ◎: Excellent, ○: Good, △: Acceptable, ×: Not Acceptable

(Examples 2 to 8) A pressure-sensitive adhesive composition of the present invention was prepared in the same manner as in Example 1 except that the mixing ratio of each component shown in Table 2 was used. The 90 ° peeling (T-peeling) adhesive strength, blocking resistance, and abrasion resistance of the information carrying sheet obtained as described above were evaluated. The evaluation results are shown in Table 2.

(Comparative Example 1) A comparison was made in the same manner as in Example 1 except that the blending amount of the fine particulate filler was larger than the upper limit of the range of the present invention and the blending ratio of each component shown in Table 3 was used. The pressure-sensitive adhesive composition was prepared, and the 90 ° peeling (T-peeling) adhesive force, blocking resistance, and abrasion resistance of the information carrying sheet obtained in the same manner as in Example 1 were evaluated. It is shown in Table 3.

(Comparative Example 2) Comparative Example 2 was carried out in the same manner as in Example 1 except that the blending amount of the fine particulate filler was made smaller than the lower limit of the range of the present invention and the blending ratio of each component shown in Table 3 was used. The pressure-sensitive adhesive composition was prepared, and the 90 ° peeling (T-peeling) adhesive force, blocking resistance, and abrasion resistance of the information carrying sheet obtained in the same manner as in Example 1 were evaluated. It is shown in Table 3.

Comparative Example 3 A comparison was made in the same manner as in Example 1 except that the blending amount of the styrene-rich SBR latex was less than the lower limit of the range of the present invention and the blending ratio of each component shown in Table 3 was used. A pressure-sensitive adhesive composition of Example 1 was prepared.
90 ° peeling (T-peeling) adhesive strength, blocking resistance, and abrasion resistance of the information carrying sheet obtained in the same manner as above were evaluated.
Table 3 shows the evaluation results.

(Comparative Example 4) A comparison was made in the same manner as in Example 1 except that the compounding amount of the fine particulate filler was larger than the upper limit of the range of the present invention and the compounding ratio of each component shown in Table 3 was used. The pressure-sensitive adhesive composition was prepared, and the 90 ° peeling (T-peeling) adhesive force, blocking resistance, and abrasion resistance of the information carrying sheet obtained in the same manner as in Example 1 were evaluated. It is shown in Table 3.

Comparative Example 5 A comparison was made in the same manner as in Example 1 except that the blending amount of the finely divided filler was smaller than the lower limit of the range of the present invention and the blending ratio of each component shown in Table 2 was used. The pressure-sensitive adhesive composition was prepared, and the 90 ° peeling (T-peeling) adhesive force, blocking resistance, and abrasion resistance of the information carrying sheet obtained in the same manner as in Example 1 were evaluated. It is shown in Table 2.

Comparative Example 6 The amount of the styrene-rich SBR latex was set to be larger than the upper limit of the range of the present invention.
A pressure-sensitive adhesive composition for comparison was prepared in the same manner as in Example 1 except that the mixing ratio of each component shown in Table 1 was used, and the information-carrying sheet obtained in the same manner as in Example 1 was peeled at 90 ° ( (T-type peeling) The adhesive strength, the blocking resistance, and the abrasion resistance were evaluated, and the evaluation results are shown in Table 3.

[0043]

[Table 2]

[0044]

[Table 3]

From Tables 2 and 3, the pressure-sensitive adhesive compositions of the present invention of Examples 1 to 8 are all excellent in 90 ° peeling (T-peeling) adhesive strength, blocking resistance and abrasion resistance. However, it can be seen that the pressure-sensitive adhesive compositions of Comparative Examples 1 to 6 are inferior in any one or two or more of them.

[0046]

The pressure-sensitive adhesive composition according to claim 1 of the present invention is a pressure-sensitive adhesive composition containing a methyl methacrylate graft copolymerized natural rubber-based latex as a main component, and is fixed on paper. Properties and cohesive force of the adhesive film are both strong.
This has a remarkable effect that the adhesive does not wear out or fall off while traveling on a printing machine or a printer.

Further, in the information carrying sheet according to the second aspect, the pressure-sensitive adhesive composition according to the first aspect is applied to a predetermined portion of the superposed surface of the base sheet by, for example, a gravure coater, and dried in a normal state by a drying treatment. Then, an adhesive layer consisting of a large number of fine convex patterns that do not adhere is formed, and when the superposed surfaces are brought into contact with each other, strong pressure is applied and adhered, and sufficient adhesive force is obtained, and if necessary, When peeling, an effect is obtained that the film can be easily peeled. The adhesive layer has a suitably strong fixing property to paper and a cohesive force of the adhesive film, and does not wear out or fall off while running a printing machine or a printer.

[Brief description of the drawings]

FIG. 1 is a surface development view of a three-fold postcard according to the present invention.

FIG. 2 is a developed rear view of the postcard of FIG. 1;

FIG. 3 is a sectional view taken along line XX of FIG. 1;

FIG. 4 is an explanatory view of the state when the postcard of FIG. 1 is folded.

FIG. 5 is a surface development view of the two-fold postcard of the present invention.

FIG. 6 is a developed rear view of the postcard of FIG. 5;

FIG. 7 is an explanatory diagram of a state when the postcard of FIG. 5 is folded.

FIG. 8 is a surface development view of a partially folded postcard according to the present invention.

FIG. 9 is a developed rear view of the postcard of FIG. 8;

FIG. 10 is an explanatory view of the state when the postcard of FIG. 8 is folded.

[Explanation of symbols]

 2, 12, 22 Base sheet 3, 3a, 3b Folding line 5 Concealment information printing 6 Peelable adhesive layer

Claims (2)

[Claims] An adhesive layer which is applied to a superposed surface of a sheet and which does not adhere in a normal state by a drying process is formed, and the superposed surfaces are brought into contact with each other and a predetermined pressure is applied thereto, whereby the superposed surface is formed. A pressure-sensitive adhesive for releasably adhering each other, wherein 100 parts by mass of a solid content of a methyl methacrylate graft copolymerized natural rubber latex has a styrene content of 70 to 95.
% Styrene-rich SBR latex having a solid content of 5%
Adhesive base 10 blended to be 50 parts by mass
A pressure-sensitive adhesive composition, characterized in that 30 to 100 parts by mass of a fine particulate filler having incompatibility with the adhesive base is mixed with 0 part by mass. 2. An information carrying sheet comprising an adhesive layer comprising a large number of fine convex patterns of the pressure-sensitive adhesive composition according to claim 1 at a predetermined portion of a superposed surface of a base sheet.